Shade treatments giving 36% full sun or less reduced both hardiness and shoot cross-sectional are... more Shade treatments giving 36% full sun or less reduced both hardiness and shoot cross-sectional area of one-year-old sour cherry (Prunus cerasus L. cv. Montmorency) and peach [Prunus persica (L.) Batsch cv. Redhaven]. Shade significantly reduced soluble carbohydrate in ‘Redhaven’.
In this experiment (in the absences of disease pressure) the application of Mycostop had no effec... more In this experiment (in the absences of disease pressure) the application of Mycostop had no effect on yield or quality of fruit harvested. Nutrient and irrigation application based on the amount of solar radiation received by the crop reduced the amount of nutrient used without reducing yield or quality. Fruit quality was higher with lower amounts of irrigation but yield increased with increased irrigation. About 2L per day was adequate to produce good yield without reducing quality in these experiments.
Six accessions of edible amaranths (Amaranthus spp. L.) of varied geographic and genotypic origin... more Six accessions of edible amaranths (Amaranthus spp. L.) of varied geographic and genotypic origin were grown in a soil enriched with 0, 50, or 100 kg·ha–1N. Leaves were harvested at 25, 35, 45, 55, and 65 days after germination (DAG) and analyzed for crude protein (CP), neutral detergent fiber (NDF), and NO3– N. In grain-bearing accessions, leaf CP content increased with N application but declined linearly over harvest dates. In vegetable types, leaf CP levels tended to fluctuate over time. In both types, NDF content declined with N application, whereas response to harvest date varied. Leaf NO3– increased two-fold in plants from fertilized plots compared to plants from unfertilized plots, but declined rapidly with time. Leaf content of NO3– did not exceed 239 mmol·kg–1 dry weight with any N fertilization treatment. Edible amaranth appeared to be adapted to soils and climate of the southeastern United States. A. tricolor was most susceptible to disease among the accessions evaluated.
Journal of the American Society for Horticultural Science
Net photosynthetic rate (Pn) of leaves of sour cherry (Prunus cerasus L. cv. Montmorency) was gre... more Net photosynthetic rate (Pn) of leaves of sour cherry (Prunus cerasus L. cv. Montmorency) was greater for leaves between nodes 9 and 13 than for either older, mature leaves or newly expanding leaves on the same shoot. For individual leaves, Pn reached maximum when the leaf was greater than 80% expanded, remained constant for 2 to 4 weeks, then gradually declined. Hyperbolic and parabolic response curves were observed in response to light and temperature, respectively. Maximum Pn occurred at light intensities between 800–1200 μEm−2s−1. Optimum temperature ranged with light level and vapor pressure deficit (YPD), but was generally between 15 to 30°C. Pn increased as CO2 concentration increased between 0 and 600 ppm, the CO2 compensation point being about 80 ppm. Under optimum conditions Pn ranged between 30 to 35 mg CO2 dm−2 hr−1.
Carotenoids are important photoprotectant and light-harvesting pigmentswithin thephotosynthetic a... more Carotenoids are important photoprotectant and light-harvesting pigmentswithin thephotosynthetic apparatus. Little information is avail-able regarding carotenoid physiology in creeping bentgrass (Agrostis stolonifera L.). Research was conducted to investigate relative high and low irradiance adaptation of creeping bentgrass with respect to b-carotene and xanthophyll composition. ‘Crenshaw ’ creeping bentgrass plants were acclimated for 7 d to relative high [47.9 mol m22 d21 photosyntheticallyactiveradation(PAR)]or lowirradiance(4.7molm22 d21 PAR). After the acclimation period, plants were transferred from high to low (low irradiance treatment) and low to high (high irradiance treatment) irradiance. Clippings were harvested at 0, 24, 72, and 168 h after the acclimation period. Zeaxanthin and antheraxanthin de-creased from 5.1 and 3.4 to 0.9 and 0.6 mg 100 g21 fresh weight (FW), respectively, over 168 h in low irradiance. As the turf adapted to low
Journal of the American Society for Horticultural Science, 1987
Le calcium semble l'ion le plus adequat pour retarder la decomposition due a Penicillium expa... more Le calcium semble l'ion le plus adequat pour retarder la decomposition due a Penicillium expansum, pour maintenir la texture et supprimer la production d'ethylene. L'application de magnesium provoque par contre des alterations a la surface des pommes
Biochemistry and molecular biology international, 1995
An exo-polygalacturonase with an isoelectric point of 4.6 and an apparent molecular weight of 45 ... more An exo-polygalacturonase with an isoelectric point of 4.6 and an apparent molecular weight of 45 kDa was isolated from apple tissue decayed by Botrytis cinerea. This isozyme had a similar isoelectric point, optimum pH, and mode of action as an isozyme produced in liquid culture by B. cinerea. The enzyme produced in the decayed tissue was less sensitive to lower pH and less inhibited by CaCl2, MgCl2, or NaCl than the enzyme produced in culture. Such changes in the properties of the enzyme produced in infected tissue could have been essential for the pathogen's successful colonization of the host tissue. Among the cations studied, calcium was the best inhibitor of PG activity.
Effet combine d'infiltrations de CaCl 2 (a differentes concentrations) et d'un entreposag... more Effet combine d'infiltrations de CaCl 2 (a differentes concentrations) et d'un entreposage sous atmosphere controlee (proportions variables de CO 2 et O 2 ) sur l'evolution, en fonction du temps, de la texture des pommes et de la sensibilite a l'infection par Penicillium expansum
Reed canary grass (Phalaris arundinacea) is a problem grass in many natural wetlands. This paper ... more Reed canary grass (Phalaris arundinacea) is a problem grass in many natural wetlands. This paper reviews the literature regarding the ecology and management of reed canary grass and presents preliminary data that suggests reduced soil-seed banks occur in wetland substrates containing a dense cover of this species. Chemical methods usually provide poor long-term control of canary grass, and most effective canary grass control techniques are not acceptable in natural areas. Because of the lack of canary grass management information, we have established a field program of control tests. Appended is a bibliography of the literature.
La fermete des fruits est en correlation avec la teneur en Ca avant et apres entreposage a 0 o C.... more La fermete des fruits est en correlation avec la teneur en Ca avant et apres entreposage a 0 o C. Le calcium a egalement un effet sur la production d'ethylene, mais qui diminue avec le temps, alors qu'il n'y a pas de relation directe entre le taux de calcium et la respiration
Tissue cultured `Heritage' raspberry plants were planted in April 1990. Split applications of... more Tissue cultured `Heritage' raspberry plants were planted in April 1990. Split applications of ammonium nitrate were made to 0.6 m widths on each side of the row at total rates of 0, 22, 45, 90, or 180 kg/ha. Applications were made in May and August in 1990 and in March and July in 1991. The plants were cut to ground level during the winter. In 1990, cane length and number of buds on the central cane were unaltered by N treatment, but all N treatments resulted in the development of more canes than the control and thus more total length of cane growth. Date of 50% accumulated yield was advanced and total yield increased with added N. Foliar N contents (2.35%) of the two highest rates were greater (3 weeks after the second application) than the control (2.12%). In 1991, early yield was slightly delayed by N. Total yield was reduced by the highest N rate. The 45 kg/ha N treatment had the highest yield of 2.53 t/ha. Plants receiving 180 kg/ha had greater foliar N content in June and ...
Shade treatments giving 36% full sun or less reduced both hardiness and shoot cross-sectional are... more Shade treatments giving 36% full sun or less reduced both hardiness and shoot cross-sectional area of one-year-old sour cherry (Prunus cerasus L. cv. Montmorency) and peach [Prunus persica (L.) Batsch cv. Redhaven]. Shade significantly reduced soluble carbohydrate in ‘Redhaven’.
In this experiment (in the absences of disease pressure) the application of Mycostop had no effec... more In this experiment (in the absences of disease pressure) the application of Mycostop had no effect on yield or quality of fruit harvested. Nutrient and irrigation application based on the amount of solar radiation received by the crop reduced the amount of nutrient used without reducing yield or quality. Fruit quality was higher with lower amounts of irrigation but yield increased with increased irrigation. About 2L per day was adequate to produce good yield without reducing quality in these experiments.
Six accessions of edible amaranths (Amaranthus spp. L.) of varied geographic and genotypic origin... more Six accessions of edible amaranths (Amaranthus spp. L.) of varied geographic and genotypic origin were grown in a soil enriched with 0, 50, or 100 kg·ha–1N. Leaves were harvested at 25, 35, 45, 55, and 65 days after germination (DAG) and analyzed for crude protein (CP), neutral detergent fiber (NDF), and NO3– N. In grain-bearing accessions, leaf CP content increased with N application but declined linearly over harvest dates. In vegetable types, leaf CP levels tended to fluctuate over time. In both types, NDF content declined with N application, whereas response to harvest date varied. Leaf NO3– increased two-fold in plants from fertilized plots compared to plants from unfertilized plots, but declined rapidly with time. Leaf content of NO3– did not exceed 239 mmol·kg–1 dry weight with any N fertilization treatment. Edible amaranth appeared to be adapted to soils and climate of the southeastern United States. A. tricolor was most susceptible to disease among the accessions evaluated.
Journal of the American Society for Horticultural Science
Net photosynthetic rate (Pn) of leaves of sour cherry (Prunus cerasus L. cv. Montmorency) was gre... more Net photosynthetic rate (Pn) of leaves of sour cherry (Prunus cerasus L. cv. Montmorency) was greater for leaves between nodes 9 and 13 than for either older, mature leaves or newly expanding leaves on the same shoot. For individual leaves, Pn reached maximum when the leaf was greater than 80% expanded, remained constant for 2 to 4 weeks, then gradually declined. Hyperbolic and parabolic response curves were observed in response to light and temperature, respectively. Maximum Pn occurred at light intensities between 800–1200 μEm−2s−1. Optimum temperature ranged with light level and vapor pressure deficit (YPD), but was generally between 15 to 30°C. Pn increased as CO2 concentration increased between 0 and 600 ppm, the CO2 compensation point being about 80 ppm. Under optimum conditions Pn ranged between 30 to 35 mg CO2 dm−2 hr−1.
Carotenoids are important photoprotectant and light-harvesting pigmentswithin thephotosynthetic a... more Carotenoids are important photoprotectant and light-harvesting pigmentswithin thephotosynthetic apparatus. Little information is avail-able regarding carotenoid physiology in creeping bentgrass (Agrostis stolonifera L.). Research was conducted to investigate relative high and low irradiance adaptation of creeping bentgrass with respect to b-carotene and xanthophyll composition. ‘Crenshaw ’ creeping bentgrass plants were acclimated for 7 d to relative high [47.9 mol m22 d21 photosyntheticallyactiveradation(PAR)]or lowirradiance(4.7molm22 d21 PAR). After the acclimation period, plants were transferred from high to low (low irradiance treatment) and low to high (high irradiance treatment) irradiance. Clippings were harvested at 0, 24, 72, and 168 h after the acclimation period. Zeaxanthin and antheraxanthin de-creased from 5.1 and 3.4 to 0.9 and 0.6 mg 100 g21 fresh weight (FW), respectively, over 168 h in low irradiance. As the turf adapted to low
Journal of the American Society for Horticultural Science, 1987
Le calcium semble l'ion le plus adequat pour retarder la decomposition due a Penicillium expa... more Le calcium semble l'ion le plus adequat pour retarder la decomposition due a Penicillium expansum, pour maintenir la texture et supprimer la production d'ethylene. L'application de magnesium provoque par contre des alterations a la surface des pommes
Biochemistry and molecular biology international, 1995
An exo-polygalacturonase with an isoelectric point of 4.6 and an apparent molecular weight of 45 ... more An exo-polygalacturonase with an isoelectric point of 4.6 and an apparent molecular weight of 45 kDa was isolated from apple tissue decayed by Botrytis cinerea. This isozyme had a similar isoelectric point, optimum pH, and mode of action as an isozyme produced in liquid culture by B. cinerea. The enzyme produced in the decayed tissue was less sensitive to lower pH and less inhibited by CaCl2, MgCl2, or NaCl than the enzyme produced in culture. Such changes in the properties of the enzyme produced in infected tissue could have been essential for the pathogen's successful colonization of the host tissue. Among the cations studied, calcium was the best inhibitor of PG activity.
Effet combine d'infiltrations de CaCl 2 (a differentes concentrations) et d'un entreposag... more Effet combine d'infiltrations de CaCl 2 (a differentes concentrations) et d'un entreposage sous atmosphere controlee (proportions variables de CO 2 et O 2 ) sur l'evolution, en fonction du temps, de la texture des pommes et de la sensibilite a l'infection par Penicillium expansum
Reed canary grass (Phalaris arundinacea) is a problem grass in many natural wetlands. This paper ... more Reed canary grass (Phalaris arundinacea) is a problem grass in many natural wetlands. This paper reviews the literature regarding the ecology and management of reed canary grass and presents preliminary data that suggests reduced soil-seed banks occur in wetland substrates containing a dense cover of this species. Chemical methods usually provide poor long-term control of canary grass, and most effective canary grass control techniques are not acceptable in natural areas. Because of the lack of canary grass management information, we have established a field program of control tests. Appended is a bibliography of the literature.
La fermete des fruits est en correlation avec la teneur en Ca avant et apres entreposage a 0 o C.... more La fermete des fruits est en correlation avec la teneur en Ca avant et apres entreposage a 0 o C. Le calcium a egalement un effet sur la production d'ethylene, mais qui diminue avec le temps, alors qu'il n'y a pas de relation directe entre le taux de calcium et la respiration
Tissue cultured `Heritage' raspberry plants were planted in April 1990. Split applications of... more Tissue cultured `Heritage' raspberry plants were planted in April 1990. Split applications of ammonium nitrate were made to 0.6 m widths on each side of the row at total rates of 0, 22, 45, 90, or 180 kg/ha. Applications were made in May and August in 1990 and in March and July in 1991. The plants were cut to ground level during the winter. In 1990, cane length and number of buds on the central cane were unaltered by N treatment, but all N treatments resulted in the development of more canes than the control and thus more total length of cane growth. Date of 50% accumulated yield was advanced and total yield increased with added N. Foliar N contents (2.35%) of the two highest rates were greater (3 weeks after the second application) than the control (2.12%). In 1991, early yield was slightly delayed by N. Total yield was reduced by the highest N rate. The 45 kg/ha N treatment had the highest yield of 2.53 t/ha. Plants receiving 180 kg/ha had greater foliar N content in June and ...
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